/**
  * Get singleton instance
  *
  * @return BP_Links_Embed
  */
 public static final function GetInstance()
 {
     if (empty(self::$instance)) {
         self::$instance = new BP_Links_Embed();
         // register natively supported services
         self::$instance->register_service(new BP_Links_Embed_Service_YouTube());
         self::$instance->register_service(new BP_Links_Embed_Service_Flickr());
         self::$instance->register_service(new BP_Links_Embed_Service_MetaCafe());
         self::$instance->register_service(new BP_Links_Embed_Service_WebPage(true));
     }
     return self::$instance;
 }